CN105549357B

CN105549357B - Powder detection device, developer remaining amount detection device, and powder detection method

Info

Publication number: CN105549357B
Application number: CN201510655627.5A
Authority: CN
Inventors: 广田哲郎; 菊地贤治; 细川浩
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2014-10-23
Filing date: 2015-10-12
Publication date: 2020-02-14
Anticipated expiration: 2035-10-12
Also published as: CN105549357A; US20160116860A1; EP3015921A1; US9523664B2

Abstract

The invention aims to provide a powder detection device, an image forming apparatus and a powder detection method, which can detect the state of a small amount of a residual developer in a container with high precision. The device detects the residual quantity in a container of powder with fluidity, and comprises a vibration plate (201) which is arranged in the container and vibrates under the influence of the powder in the container; and a magnetic flux sensor (10) that detects a vibration state of the vibration plate (201); and an agitating member (205) that causes the vibrating plate (201) to vibrate, and detects the remaining amount of powder in the container based on the detection result of the magnetic flux sensor (10).

Description

Powder detection device, developer remaining amount detection device, and powder detection method

Technical Field

The invention relates to a powder detection device, a developer remaining amount detection device and a powder detection method.

Background

In recent years, the electronization of information has been promoted, and image forming apparatuses such as printers, facsimile machines, and scanners for electronizing documents for outputting electronized information have become indispensable. In such an image forming apparatus, an electrophotographic method is known as a method of forming and outputting an image by developing an electrostatic latent image formed on a photoreceptor and transferring the formed image onto a sheet of paper.

In an electrophotographic image forming apparatus, a developer for developing an electrostatic latent image formed on a photoreceptor is supplied from a container as a supply source of the developer. As a method for detecting the remaining amount of the developer supplied in this manner, for example, a method has been proposed in which a member for stirring the developer deforms a sheet to be pressed, and a change in a member to be detected in accordance with the deformation of the sheet to be pressed is referred to (see patent document 1).

In the method disclosed in patent document 1, the amount of toner in the container with respect to the deformation of the pressurized sheet is not limited to be reflected in the same manner. Further, there is a problem in detection accuracy of a temporal change of the sheet to be pressed, adhesion of the developer to the sheet to be pressed, and the like.

[ patent document 1 ] Japanese laid-open patent publication No. 2013-37280

Disclosure of Invention

In view of the above circumstances, an object of the present invention is to detect a state in which the amount of the developer remaining in the container is small with high accuracy.

In order to solve the above problem, one aspect of the present invention is a powder detection device for detecting a remaining amount in a container of a powder having fluidity, the powder detection device including: a vibrating section that is disposed inside the container and vibrates under the influence of the powder inside the container; a vibration detection unit that detects a vibration state of the vibration unit; a vibration imparting portion that causes the vibrating portion to vibrate; and a detection processing unit that detects the remaining amount of the powder in the container based on a detection result of the vibration detection unit.

According to the present invention, it is possible to detect a state in which the amount of the developer remaining in the container is small with high accuracy.

Drawings

Fig. 1 is a schematic view showing a mechanical configuration of an image forming apparatus including a developing unit on which a magnetic flux sensor according to an embodiment of the present invention is mounted.

Fig. 2 is a perspective view showing a toner supply structure according to the embodiment of the present invention.

Fig. 3 is a perspective view showing an overview of the sub-hopper according to the embodiment of the present invention.

Fig. 4 is a perspective view showing an overview of the sub-hopper according to the embodiment of the present invention.

Fig. 5 is a schematic circuit diagram of a magnetic flux sensor according to an embodiment of the present invention.

Fig. 6 is a schematic view showing a counting method of output signals of the magnetic flux sensor according to the embodiment of the present invention.

Fig. 7 is a perspective view showing an overview of a magnetic flux sensor according to an embodiment of the present invention.

Fig. 8 is a block diagram showing a configuration of a controller for acquiring a signal of a magnetic flux sensor according to an embodiment of the present invention.

Fig. 9 is a schematic view showing the arrangement relationship between the magnetic flux sensor and the diaphragm according to the embodiment of the present invention.

Fig. 10 is a schematic view showing the action of magnetic flux when passing through the vibrating plate according to the embodiment of the present invention.

Fig. 11 is a schematic view showing the oscillation frequency of the magnetic flux sensor according to the distance between the vibrating plate and the magnetic flux sensor according to the embodiment of the present invention.

Fig. 12 is a perspective view showing the arrangement of the diaphragm and the metal rod according to the embodiment of the present invention.

Fig. 13 is a side view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 14 is a side view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 15 is a top view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 16 is a side view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 17 is a top view showing a vibration state of the vibrating plate according to the embodiment of the present invention.

Fig. 18 is a side view showing a relationship between the vibrating state of the vibrating plate and the developer in the embodiment of the present invention.

Fig. 19 is a schematic diagram showing a change with time of a count value of the oscillation frequency of the magnetic flux sensor that changes in correspondence with the damping of the vibration of the vibrating plate according to the embodiment of the present invention.

Fig. 20 is a flowchart illustrating an operation of detecting the remaining toner amount according to the embodiment of the present invention.

Fig. 21 is a schematic diagram showing an analysis method of the count value according to the embodiment of the present invention.

Fig. 22 is a schematic diagram showing a relationship between a sampling period of a count value and a vibration period of a vibrating plate according to the embodiment of the present invention.

Fig. 23 is a schematic view showing the interval between the magnetic flux sensor and the vibrating plate according to the embodiment of the present invention.

Fig. 24 is a view showing an example of the arrangement heights of the magnetic flux sensor and the diaphragm according to the embodiment of the present invention.

Fig. 25 is a view showing an example of the arrangement heights of the magnetic flux sensor and the diaphragm according to the embodiment of the present invention.

Fig. 26 is a diagram illustrating a case where the magnetic flux sensor and the vibrating plate according to the embodiment of the present invention are used in the developing device.

Fig. 27 is another exemplary side view of the coil according to the embodiment of the present invention.

Fig. 28 is another exemplary front view of the coil according to the embodiment of the present invention.

Fig. 29 is an explanatory view of a diaphragm according to an embodiment of the present invention.

Fig. 30 is an explanatory view of a diaphragm according to an embodiment of the present invention.

Fig. 31 is an explanatory view of a diaphragm according to an embodiment of the present invention.

Fig. 32 is an explanatory view of the diaphragm according to the embodiment of the present invention.

Fig. 33 is a perspective view showing an overview of the sub-hopper according to the embodiment of the present invention.

Fig. 34 is a perspective view showing the arrangement of the diaphragm and the metal rod according to the embodiment of the present invention.

Fig. 35 is a side view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 36 is a side view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 37 is a top view showing the arrangement relationship between the vibrating plate and the stirring member according to the embodiment of the present invention.

Fig. 38 is a perspective view showing the arrangement of the diaphragm and the metal rod according to the embodiment of the present invention.

Fig. 39 is a schematic view showing the range of removing the color-developer by the metal rod according to the embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, the description has been given of an example in which the remaining amount of toner in a sub hopper that holds toner between a developing device that develops an electrostatic latent image formed on a photoreceptor and a container that is a supply source of toner for developer is detected in an electrophotographic image forming apparatus.

Fig. 1 is a side view showing a mechanism for forming and outputting an image included in the image forming apparatus 100 according to the present embodiment. As shown in fig. 1, the image forming apparatus 100 according to the present embodiment includes image forming sections 106K to 106Y in which respective colors are arranged along a conveying belt 105 as an endless moving mechanism, and is of a so-called tandem type. That is, along a conveyance belt 105 on which an intermediate transfer image is formed for transfer to a sheet (a type of recording medium) 104 fed separately from a sheet feed tray 101 by a sheet feed roller 102, a plurality of image forming units (electrophotographic processing units) 106Y, 106M, 106C, and 106K (hereinafter collectively referred to as image forming units 106) are arranged in this order from the upstream side in the conveyance direction of the conveyance belt 105.

Further, the paper 104 fed from the paper feed tray 101 is once stopped by the registration rollers 103, and is fed to the image transfer position on the conveyance belt 105 after timing of image formation in the image forming unit 106.

The plurality of

image forming units

106Y, 106M, 106C, and 106K have a common internal configuration except for the color of the formed toner image. Although the image forming section 106K forms a black image, the image forming section 106M forms a magenta image, the image forming section 106C forms a cyan image, and the image forming section 106Y forms a yellow image, in the following description, only the image forming section 106Y will be specifically described, but the other

image forming sections

106M, 106C, and 106K are the same as the image forming section 106Y, and only symbols distinguished by M, C, K are displayed in the drawings for the respective constituent elements of the

image forming sections

106M, 106C, and 106K instead of Y given to the respective constituent elements of the image forming section 106Y, and the description thereof will be omitted.

The conveying belt 105 is an endless belt that is stretched over a drive roller 107 and a driven roller 108 that are driven to rotate, that is, an endless belt. The driving roller 107 is rotationally driven by a driving motor, not shown, and the driving motor, the driving roller 107, and the driven roller 108 function as a driving mechanism for moving the conveying belt 105 of the endless moving mechanism.

In image formation, the first image forming section 106 transfers a black toner image to the conveying belt 105 which is driven to rotate. The image forming unit 106 includes a photosensitive drum 109Y as a photosensitive body, and a charger 110Y, an optical writing device 111, a developing device 112Y, a photosensitive body cleaner 113Y, a charge remover (not shown), and the like disposed around the photosensitive drum 109Y. The optical writing device 111 is configured to irradiate the

photosensitive drums

109Y, 109M, 109C, and 109K (hereinafter collectively referred to as "photosensitive drums 109") with light.

In image formation, the outer peripheral surface of the photosensitive drum 109Y is uniformly charged in the dark by the charger 110Y, and then written by light from the light writing device 111 from a light source corresponding to a yellow image, thereby forming an electrostatic latent image. The developer 112Y visualizes the electrostatic latent image with yellow toner, and thus forms a yellow toner image on the photosensitive drum 109Y.

The toner image is transferred to the conveying belt 105 by the action of the transfer device 115Y at a position (transfer position) where the photosensitive drum 109Y and the conveying belt 105 abut on or are closest to each other. By this transfer, an image made of yellow toner is formed on the conveying belt 105. After the transfer of the toner image is completed, the photoreceptor drum 109Y wipes off unnecessary toner remaining on the outer peripheral surface by the photoreceptor cleaner 113Y, and after the removal by the remover, the next image formation is prepared.

As described above, the yellow toner image transferred onto the conveying belt 105 by the image forming unit 106Y is conveyed to the next image forming unit 106M by the roller drive of the conveying belt 105. In the image forming section 106M, a magenta toner image is formed on the photosensitive drum 109M by the same process as the image forming process of the image forming section 106Y, and the toner image is transferred to be superimposed on the yellow image that has been formed.

The yellow and magenta toner images transferred onto the conveying belt 105 are further conveyed to the next

image forming units

106C and 106K, and by the same operation, the cyan toner image formed on the photosensitive drum 109C and the black toner image formed on the photosensitive drum 109K are superimposed and transferred onto the image that has been transferred. In this way, a full-color intermediate transfer image is formed on the conveying belt 105.

The sheets 104 stored in the sheet feed tray 101 are sequentially fed from the uppermost surface, and the intermediate transfer image formed on the conveyance belt 105 is transferred to the sheet surface at a position where the conveyance path contacts the conveyance belt 105 or a position closest thereto. This forms an image on the paper surface of the paper 104. The sheet 104 on which the image is formed is further conveyed, and the image is fixed by the fixing device 116, and then discharged to the outside of the image forming apparatus.

Further, a belt cleaner 118 is provided to the conveying belt 105. As shown in fig. 1, the belt cleaner 118 is a cleaning blade that is pressed against the conveyance belt 105 on the upstream side of the photosensitive drum 109 on the downstream side of the transfer position of the image from the conveyance belt 105 to the paper 104, and is a developer removing portion that scrapes off the toner adhering to the surface of the conveyance belt 105.

First, a configuration for supplying toner into the developing unit 112 will be described with reference to fig. 2. The toner supply configuration is substantially common to each of CMYK colors, and fig. 2 shows the supply configuration to one developing unit 112. The toner is accommodated in the toner tank 117, and as shown in fig. 2, the toner is supplied from the toner tank 117 into the sub hopper 200 through the toner tank supply path 120.

The sub hopper 200 temporarily holds the toner supplied from the toner tank 117, and supplies the toner to the developing device 112 according to the remaining amount of the toner in the developing device 112. Then, the toner is supplied from the sub hopper 200 into the developer 112 via the sub hopper supply path 119. The gist of the present embodiment is to detect a state of a decrease in the amount of toner in the sub hopper 200 when the sub hopper 200 cannot supply toner after the toner in the toner tank 117 is used up.

Fig. 3 is a perspective view showing an overview of the sub-hopper 200 according to the embodiment of the present invention. As shown in fig. 3, a magnetic flux sensor 10 is attached to an outer wall of a housing constituting the sub hopper 200. In fig. 3, the upper portion of the sub hopper 200 is an opening, and a cover formed with the toner tank supply path 120 is attached to the opening. Further, the toner held inside the sub hopper 200 is fed out from the sub hopper supply path 119 as shown in fig. 3.

Fig. 4 is a perspective view showing the inside of the sub-hopper 200. As shown in fig. 4, a vibration plate 201 is provided on an inner wall of the sub hopper 200. The inner wall on which the diaphragm 201 is provided is the back side of the outer wall on which the magnetic flux sensor 10 is mounted in fig. 3. Therefore, the vibration plate 201 is disposed opposite to the magnetic flux sensor 10.

The vibrating plate 201 is a rectangular plate-like member, and one end in the longitudinal direction thereof is arranged in a cantilever state fixed to the frame of the sub-hopper 200. Further, a projection 202 is disposed at an end portion of the diaphragm 201 on the side not fixed in the longitudinal direction.

The protrusion 202 has a function of adjusting a vibration frequency of the vibration plate 201 when vibrating, or a function of vibrating the vibration plate 201. Further, a metal rod 203 is disposed near the diaphragm 201. The function of the metal rod 203 will be explained later.

The sub hopper 200 is provided with a rotation shaft 204 and a stirring member 205 as a structure for stirring the toner inside. The rotation shaft 204 is a shaft that rotates inside the sub hopper 200. The stirring member 205 is fixed to the rotation shaft 204, and the stirring member 205 rotates with the rotation of the rotation shaft 204 to stir the toner in the sub hopper 200. The longitudinal direction of the diaphragm 201 is arranged substantially parallel to the axial direction of the rotation shaft 204.

The stirring member 205 also has a function of ejecting the projection 202 provided on the vibrating plate 201 in addition to stirring the toner. Thus, the projection 202 is flicked and causes the vibration plate 201 to vibrate every 1 revolution of the stirring member 205. That is, the stirring member 205 functions as a vibration imparting portion while the vibration plate 201 functions as a vibration portion. The gist of the present embodiment is to detect the vibration of the vibration plate 201, thereby detecting the remaining amount of toner in the sub hopper 200.

Next, the internal structure of the magnetic flux sensor 10 according to the present embodiment will be described with reference to fig. 5. As shown in fig. 5, the magnetic flux sensor 10 according to the present embodiment is an oscillation circuit based on a Colpitts (Colpitts) type LC oscillation circuit, and includes a planar pattern coil 11, a pattern impedance 12, a first capacitor 13, a second capacitor 14, a feedback impedance 15,

unbuffered ICs

16, 107, and an output terminal 18.

The planar pattern coil 11 is a planar coil formed by signal lines printed in a planar pattern on a base plate constituting the magnetic flux sensor 10. As shown in fig. 5, the planar pattern coil 11 has an inductance L obtained by a coil. The value of the inductance L of the planar pattern coil 11 varies according to the magnetic flux of the space facing the plane on which the coil is formed. As a result, the magnetic flux sensor 10 according to the present embodiment generates a frequency signal corresponding to the magnetic flux passing through the space where the coil surfaces of the planar pattern coil 11 face each other as an oscillating unit.

The pattern impedance 12 and the planar pattern coil 11 are similarly impedances formed by signal lines printed in a planar pattern on the substrate. The pattern impedance 12 according to the present embodiment is formed in a winding pattern, and thus a state in which a current flows more easily than in a linear pattern is formed. The pattern impedance 12 is one of the gist of the present embodiment. In other words, the winding shape is a shape that is bent after reciprocating a plurality of times in a predetermined direction. As shown in FIG. 5, the pattern impedance 12 has a resistance value R_P. As shown in fig. 5, a planar pattern coil11 and pattern resistance 12 are connected in series.

The first capacitor 13 and the second capacitor 14 are capacitors that constitute a koppez-type LC oscillation circuit together with the planar pattern coil 11. Therefore, the first capacitor 13 and the second capacitor 14 are connected in series with the planar pattern coil 11 and the pattern impedance 12. A resonant current loop is formed by a loop formed by the planar pattern coil 11, the pattern impedance 12, the first capacitor 13, and the second capacitor 14.

The feedback impedance 15 is inserted to stabilize the bias voltage. By the functions of the unbuffered IC16 and the unbuffered IC17, a variation in potential of a part of the resonant current loop is output from the output terminal 18 as a rectangular wave corresponding to the resonant frequency.

With such a configuration, the magnetic flux sensor 10 according to the present embodiment is configured to correspond to the inductance L and the resistance R_PThe frequency f of the capacitance C of the first capacitor 13 and the second capacitor 14 oscillates (Oscillation). The frequency can be expressed by the following equation (1).

Formula (1)

Then, the inductance L also changes due to the presence or concentration of a magnetic substance in the vicinity of the planar pattern coil 11. Therefore, the magnetic permeability in the space near the planar pattern coil 11 can be determined by the oscillation frequency of the magnetic flux sensor 10.

As described above, the magnetic flux sensor 10 in the sub-hopper 200 according to the present embodiment is disposed facing the vibration plate 201 via the casing. Accordingly, the magnetic flux generated by the planar pattern coil 11 passes through the vibration plate 201. That is, the vibration plate 201 affects the magnetic flux generated by the planar pattern coil 11 and affects the inductance L. Eventually, the presence of the vibration plate 201 affects the frequency of the oscillation signal of the magnetic flux sensor 10. This is one of the gist of the present embodiment. Details will be described later.

Fig. 6 is a schematic diagram showing a manner of counting the output signal of the magnetic flux sensor 10 according to the present embodiment. If there is no change in the magnetic flux occurring through the planar pattern coil 11 contained in the magnetic flux sensor 10, the magnetic flux sensor 10 will in principle continue to oscillate at the same frequency. As a result, as shown in fig. 6, the count value of the counter increases as time elapses, and as shown in fig. 6, the count values of aaaaah, bbbbbbbh, ccch, dddddddh, and aaaaah are acquired at respective times t1, t2, t3, t4, and t 5.

By calculating the count value at each time from each period of T1, T2, T3, T4, etc. shown in fig. 6, the frequency at each period can be obtained. For example, when the frequency of the magnetic flux sensor 10 is calculated by counting the reference clock corresponding to 2(msec) and outputting the interrupt signal, the oscillation frequency f (hz) of the magnetic flux sensor 10 in each period, such as T1, T2, T3, and T4 shown in fig. 6, is calculated by dividing the count value in each period by 2 (msec).

In addition, as shown in fig. 6, when the upper limit of the count value of the counter is FFFFh, when the frequency in the period T4 is calculated, the oscillation frequency f (hz) can be calculated by dividing the sum of the value obtained by subtracting dddddh from FFFFh and the value of AAAAh by 2 (msec).

As described above, in the image forming apparatus 100 according to the present embodiment, the frequency of the signal oscillated by the magnetic flux sensor 10 is acquired, and a phenomenon corresponding to the oscillation frequency of the magnetic flux sensor 10 can be determined based on the acquired result. Then, in the magnetic flux sensor 10 according to the present embodiment, the inductance L changes depending on the state of the diaphragm 201 disposed opposite to the planar pattern coil 11, and as a result, the frequency of the signal output from the output terminal 18 changes.

As a result, the controller that acquires the signal can check the state of the diaphragm 201 disposed opposite to the planar pattern coil 11. One of the gist of the present embodiment is to determine the state of the developer inside the sub hopper 200 based on the state of the vibrating plate 201 thus confirmed.

Although the frequency is obtained by dividing the count value of the oscillation signal by the period as described above, the obtained count value may be used as it is as a parameter for displaying the frequency if the period for obtaining the count value is fixed.

Fig. 7 is a perspective view showing an overview of the magnetic flux sensor 10 according to the present embodiment. In fig. 7, the plane on which the planar pattern coil 11 and the pattern impedance 12 shown in fig. 5 are formed, that is, the detection plane facing the space where the magnetic permeability needs to be detected faces upward.

As shown in fig. 7, pattern resistors 12 connected in series to the planar pattern coil 11 are printed and wired on the detection surface on which the planar pattern coil 11 is formed. As illustrated in fig. 5, the planar pattern coil 11 is a pattern of signal lines formed in a spiral shape on a plane. The pattern impedance 12 is a pattern of signal lines formed in a winding shape on a plane, and the function of the magnetic flux sensor 10 as described above is realized by these patterns.

The portion formed by the planar pattern coil 11 and the pattern impedance 12 is a detection portion of magnetic permeability in the magnetic flux sensor 10 according to the present embodiment. When the magnetic flux sensor 10 is mounted to the sub-hopper 200, the detection portion is mounted to face the vibration plate 201.

Next, a configuration of acquiring an output value of the magnetic flux sensor 10 in the image forming apparatus 100 according to the present embodiment will be described with reference to fig. 8. Fig. 8 is a block diagram showing the controller 20 and the magnetic flux sensor 10 for acquiring the output value of the magnetic flux sensor 10. As shown in fig. 8, the controller 20 according to the present embodiment includes a cpu (central processing unit)20, an ASIC (application Specific Integrated circuit)22, a timer 23, a crystal oscillator circuit 24, and an input/output control ASIC 30.

The CPU10 is a computing device that performs computation based on a program stored in a storage medium such as a rom (read Only memory) to control the operation of the entire controller 20. The ASIC22 is used as a connection interface for connecting a system bus of the CPU21 or ram (random access memory) and other devices.

The timer 23 generates an interrupt signal and outputs the interrupt signal to the CPU21 every time the count value of the reference clock input from the crystal oscillator circuit 24 becomes a predetermined value. The CPU21 outputs a read signal for acquiring the output value of the magnetic flux sensor 10 in response to the interrupt signal input from the timer 23. The crystal oscillator circuit 24 generates a reference clock for operating each device inside the controller 20.

The input/output control ASIC30 acquires the detection signal output from the magnetic flux sensor 10, and converts the acquired detection signal into data that can be processed inside the controller 20. As shown in fig. 8, the input/output control ASIC30 includes a magnetic permeability counter 31, a read signal acquisition section 32, and a count value output section 33. As described above, the magnetic flux sensor 10 according to the present embodiment is an oscillation circuit that outputs a rectangular wave having a frequency corresponding to the magnetic permeability in the space to be detected.

The magnetic permeability counter 31 is a counter that increments a value corresponding to the rectangular wave output by such a magnetic flux sensor 10. That is, the magnetic permeability counter 31 functions as a target signal counter that counts the number of signals of a signal to be frequency-calculated. Since the magnetic flux sensor 10 according to the present embodiment is provided for each sub hopper 200 connected to the developers 112 of CMYK colors, a plurality of magnetic permeability counters 31 are provided.

The read signal acquisition section 32 acquires, via the ASIC22, a read signal that is an acquisition instruction of the count value of the magnetic permeability counter 31 issued by the CPU 20. The read signal acquiring unit 32 acquires the read signal from the CPU21, and then inputs a signal for outputting a count value to the count value output unit 33. The count value output unit 33 outputs the count value of the counter 31 based on the signal from the read signal acquisition unit 32.

Also, access to the input/output control ASIC30 from the CPU21 can be performed by means of a register, for example. Therefore, the CPU10 writes the value into a predetermined register included in the input/output control ASIC30 to read the signal. The output of the count value by the count value output unit 33 is performed after the count value is stored in a predetermined register included in the input/output control ASIC30 and the CPU21 acquires the count value. The controller 20 shown in fig. 8 may be provided separately from the magnetic flux sensor 10, or may be mounted on the bottom plate of the magnetic flux sensor 10 as a circuit including the CPU 21.

In such a configuration, the CPU21 detects the vibration state of the vibrating plate 201 from the count value obtained from the count value output unit 33, and detects the remaining amount of toner in the sub hopper 200 from the detection result. That is, the CPU21 performs calculation in accordance with a predetermined program to constitute a detection processing unit. The count value obtained from the count value output unit 33 is also used as frequency-related information indicating the frequency of the magnetic flux sensor 10 that changes in accordance with the vibration of the diaphragm 201.

Next, the influence of the diaphragm 201 on the oscillation frequency of the magnetic flux sensor 10 according to the present embodiment will be described. As shown in fig. 9, in the magnetic flux sensor 10, the surface on which the planar pattern coil 11 is formed and the vibrating plate 201 are arranged facing each other with the frame of the sub-hopper 200 interposed therebetween. Then, as shown in fig. 9, a magnetic flux is generated with the center of the planar pattern coil 11 as the center, and the magnetic flux penetrates the vibration plate 201.

The vibration plate 201 may be made of SUS plate, and as shown in fig. 10, an eddy current is generated in the vibration plate 201 by the magnetic flux G1 penetrating the vibration plate 201. This eddy current generates a magnetic flux G2, which acts to cancel the magnetic flux G1 of the planar pattern coil 11. Thus, since the magnetic flux G1 is cancelled, the inductance L in the magnetic flux sensor 10 decreases. As shown in the above equation (1), when the inductance L decreases, the oscillation frequency f increases.

The magnitude of the eddy current generated in the vibration plate 201 by the magnetic flux of the planar pattern coil 11 varies depending on the distance between the planar pattern coil 11 and the vibration plate 201 in addition to the intensity of the magnetic flux. Fig. 11 is a schematic diagram showing the oscillation frequency of the magnetic flux sensor 10 corresponding to the distance of the planar pattern coil 11 and the vibration plate 201.

The magnitude of the eddy current generated inside the vibration plate 201 is inversely proportional to the interval between the planar pattern coil 11 and the vibration plate 201. Therefore, as shown in fig. 11, the narrower the interval between the planar pattern coil 11 and the vibration plate 201, the higher the oscillation frequency of the magnetic flux sensor 10, and if the interval is narrower than a predetermined interval, the inductance L is too low to oscillate (oscillate).

In the sub-hopper 200 according to the present embodiment, the vibration of the vibrating plate 201 is detected from the oscillation frequency of the magnetic flux sensor 10 by using the characteristics shown in fig. 11. The gist of the present embodiment is to detect the remaining amount of toner in the sub hopper 200 based on the vibration of the vibration plate 201 thus detected. That is, the vibrating plate 201 and the magnetic flux sensor 10 shown in fig. 9, and the configuration for processing the output signal of the magnetic flux sensor 10 are used as the powder detection device according to the present embodiment. The powder detection device is used for detecting the residual amount of the toner, namely the residual amount of the developer. In addition, the magnetic flux sensor 10 functions as a vibration detection unit.

The vibration of the vibration plate 201 flicked by the stirring member 205 can be represented by a natural vibration frequency determined by the rigidity of the vibration plate 201 or the weight of the bump 202 and an attenuation rate determined by an external element absorbing the vibration energy. As external elements for absorbing this vibration energy, there are fixing factors such as fixing strength and air resistance of a fixing portion for fixing the vibration plate 201 in a cantilever state, and toner that contacts the vibration plate 201 inside the sub hopper 200.

The toner contacting the vibration plate 201 inside the sub hopper 200 fluctuates due to the remaining amount of toner inside the sub hopper 200. Therefore, by detecting the vibration of the vibration plate 201, the remaining amount of toner in the sub hopper 200 can be detected. Therefore, in the sub hopper 200 according to the present embodiment, the stirring member 205 for stirring the toner inside pops the vibration plate 201, and periodically vibrates the vibration plate 201 according to the rotation.

Next, the arrangement of the components around the vibrating plate 201 inside the sub-hopper 200 and the configuration in which the stirring member 205 is used to pop up the vibrating plate 201 will be described. Fig. 12 is a perspective view showing the arrangement of the periphery of the vibration plate 201. As shown in fig. 12, the vibrating plate 201 is fixed to the frame of the sub-hopper 200 by a fixing portion 201 a.

Fig. 13 is a side view showing a state before the stirring member 205 comes into contact with the projection 202 attached to the vibration plate 201 as a rotation state of the rotation shaft 204. In fig. 13, the rotation shaft 204 and the stirring member 205 are rotated in the clockwise rotation direction.

As shown in fig. 13, the projection 202 is a protruding portion protruding from the plate surface of the diaphragm 201, and has a shape inclined with respect to the plate surface of the diaphragm 201 when viewed from the side. The inclination is formed such that the inclined surface thereof is closer to the rotation shaft 204 along the rotation direction of the stirring member 205. The inclined surface of the projection 202 is a portion pressed by the stirring member 205 when the stirring member 205 is flicked and the vibration plate 201 is vibrated. Fig. 14 is a side view showing a state in which the stirring member 205 further rotates from the state shown in fig. 13.

The stirring member 205 further rotates in contact with the projection 202, and the vibration plate 201 is pressed and deformed as the projection 202 is inclined. In fig. 14, the positions of the diaphragm 201 and the bump 202 in a stable state when no external force is applied are shown by broken lines. As shown in fig. 14, the vibrating plate 201 and the projection 202 are pressed by the stirring member 205.

Fig. 15 is a top view showing the state shown in fig. 14. Since the vibration plate 201 is fixed to the frame of the sub-hopper 200 by the fixing portion 201a, the position of the fixing portion 201a side does not change. On the other hand, the end opposite to the free end where the projection 202 is provided is pushed by the stirring member 205 and then moves on the side opposite to the side where the rotation shaft 204 is provided. As a result, the diaphragm 201 is bent with the fixing portion 201a as a base point as shown in fig. 15. In the state of being thus bent, energy for vibrating the vibration plate 201 is accumulated.

As shown in fig. 15, the stirring member 205 according to the present embodiment is provided with a wedge 205a between a portion in contact with the projection 202 and other portions. This prevents the stirring member 205 from being damaged by an excessive force applied when the stirring member 205 presses the projection 202.

Further, a circular portion 205b is provided at the start point of the wedging 205 a. Thus, when the amount of curvature of the stirring member 205 differs at the wedge 205a as the boundary, the stress applied to the starting point of the wedge 205a can be reflected, and the stirring member 205 can be prevented from being damaged.

Fig. 16 is a side view showing a state in which the stirring member 205 further rotates from the state shown in fig. 14. In fig. 16, the position of the vibration plate 201 in the stable state is indicated by a broken line, and the position of the vibration plate 201 shown in fig. 14 is indicated by a chain line. The position of the vibrating plate 201, which is bent to the opposite side when the vibration energy accumulated by being pressed by the stirring member 205 is released, is shown by a solid line.

Fig. 17 is a top view of the state shown in fig. 16. As shown in fig. 16, when the pressing of the stirring member 205 against the projection 202 is released, the end portion on the side where the projection 202 is provided as the free end moves in a curved manner on the opposite side by the energy of the curve accumulated in the vibrating plate 201.

In the state of fig. 16 and 17, the vibration plate 201 is in a state of being away from the magnetic flux sensor 10 facing through the frame of the sub-hopper 200. After that, the vibration plate 201 repeats a state closer to the stable state and a state farther from the stable state with respect to the magnetic flux sensor 10 by the vibration, and returns to the stable state due to the attenuation of the vibration.

Fig. 18 is a view schematically showing toner held in the sub hopper 200 in dot patterns (dots). As shown in fig. 18, when toner exists in the sub hopper 200, the vibration plate 201 or the protrusion 202 vibrates and comes into contact with the toner. Therefore, the vibration of the vibration plate 201 is more quickly attenuated than in the case where no toner exists inside the sub hopper 200. The remaining amount of toner in the sub hopper 200 can be detected from the change in the attenuation of the vibration.

Fig. 19 is a schematic diagram showing changes in the count value of the oscillation signal of the magnetic flux sensor 10 during each predetermined period after the projection 202 is sprung open by the stirring member 205 until the vibration of the vibrating plate 201 is damped until the vibration stops. The higher the oscillation frequency, the more the count value of the oscillation signal of the magnetic flux sensor 10 will be. Therefore, the vertical axis of fig. 19 may replace the count value with the oscillation frequency.

As shown in fig. 19, at timing t1, the vibrating plate 201 approaches the magnetic flux sensor 10 because the stirring member 205 contacts and presses the projection 202. As a result, the oscillation frequency of the magnetic flux sensor 10 increases, and the count value increases for each predetermined period.

Then, at timing t2, the pressing of the stirring member 205 against the projection 202 is released, and thereafter, the vibration is caused by the vibration energy accumulated in the vibration plate 201. By the vibration of the vibration plate 201, the interval between the vibration plate 201 and the magnetic flux sensor 10 repeats a state wider than it and a state narrower than it centering on the stable state. As a result, the frequency of the oscillation signal of the magnetic flux sensor 10 vibrates in accordance with the vibration of the vibrating plate 201, and the count value in each predetermined period also vibrates similarly.

The amplitude of the vibration plate 201 becomes gradually smaller as the vibration energy is consumed. That is, the vibration of the vibration plate 201 is attenuated together with time. Therefore, the change in the interval between the diaphragm 201 and the magnetic flux sensor 10 is also reduced with the passage of time, and as shown in fig. 19, the temporal change in the count value is also changed in the same manner.

Here, as described above, the more the toner remaining amount inside the sub hopper 200, the faster the vibration of the vibration plate 201 is attenuated. Therefore, by analyzing the manner of damping the vibration of the oscillation signal of the magnetic flux sensor 10 shown in fig. 19, it is possible to know how the vibration of the vibration plate 201 is damped, and thus the remaining amount of toner in the sub hopper 200 can be known.

Therefore, as shown in fig. 19, when the peak values of the count values of the oscillation signals are P1, P2, P3, P4, and ζ, the damping rate ζ of the vibration of the diaphragm 201 can be obtained by the following expression (2). As shown in equation (2), by referring to the ratio of the peak values at different timings, it is possible to remove the error due to the environmental variation and obtain an accurate attenuation ratio. In other words, the CPU21 according to the present embodiment obtains the attenuation rate ζ from the ratio of the count values obtained at different timings.

Formula (2)

In addition, the above expression (2) uses P1, P2, P5, and P6 among the peaks shown in fig. 19, but this is only one example, and other peaks may be used. However, the peak at the timing t2 when the diaphragm 201 is pressed by the stirring member 205 and is closest to the magnetic flux sensor 10 is not suitable as a calculation target because it includes an error in which the interference of the sliding movement due to the friction between the stirring member 205 and the projection 202 is superimposed.

As shown in fig. 18, even if the damping of the vibration is accelerated by the presence of the toner inside the sub hopper 200, the vibration frequency of the vibration plate 201 does not change greatly. Therefore, by calculating the amplitude ratio of the specific peak value shown in the above expression (2), the attenuation of the amplitude in the predetermined period can be obtained.

Next, the operation of detecting the remaining toner amount in the sub hopper 200 according to the present embodiment will be described with reference to the flowchart of fig. 20. The actions of the flowchart shown in fig. 20 are the actions of the CPU21 shown in fig. 8. As shown in fig. 20, the CPU21 first detects that the projection 202 is pressed by the stirring member 205 and vibrated as shown in fig. 14 (step S2201).

As described above, the CPU21 obtains the count value of the output signal of the magnetic flux sensor 10 for each predetermined period from the count value output unit 33. This count value is C0 shown in fig. 19 in the steady state. On the other hand, as shown in fig. 14, when the projection 202 is pressed, the count value is increased as the diaphragm 201 approaches the magnetic flux sensor 10. Therefore, the CPU21 detects that vibration has occurred in step S2201 when the count value obtained from the count value output unit 33 exceeds a predetermined threshold value.

The CPU21 continues the process of acquiring the count value for each predetermined period as a normal process before and after step S2201. Then, after step S2201, the CPU21 obtains a vibration peak value corresponding to the count value of the vibration plate 201 shown in fig. 19 (step S2202). In step S2202, the CPU21 determines a peak value by continuing to analyze the count value acquired every predetermined period.

Fig. 21 is a view showing an analysis method of the count values, and the count values acquired in the respective predetermined periods are displayed with "number n" and "count value Sn" of the respective count values in the order of acquisition, and with the symbols "Sn-1-Sn" of the difference from the previous count value. In the results shown in FIG. 21, the value immediately before the sign inversion of "Sn-1-Sn" is a peak value. In fig. 21, No. 5 and No. 10 are employed as the peak values.

That is, the CPU21 calculates "Sn-1 to Sn" shown in fig. 21 for the count values sequentially acquired after step S2201. Then, the "count value Sn" at the timing immediately before the sign inversion obtained as the calculation result is used as the peak values of P1, P2, P3, and the like shown in fig. 19.

As described above, the value at the timing t2 is preferably avoided. The value of the timing t2 is the first peak after step S2201. Therefore, the CPU21 discards the first value from the extracted peaks after the analysis shown in fig. 21.

Further, since the actually obtained count value may contain noise of a high frequency component, there is a possibility that the sign of "Sn-1-Sn" is inverted at a position other than the peak of the vibration caused by the vibration plate 201. In order to avoid false detection in this case, it is preferable that the CPU21 performs the smoothing process on the value obtained from the count value output unit 33 and then performs the analysis shown in fig. 21. The smoothing process may be a general process such as a moving average method.

After the peak value is obtained in this manner, the CPU21 calculates the attenuation ratio ζ by the calculation of the above expression (2) (step S2203). Therefore, in step S2202, the count value is analyzed in the manner shown in fig. 21 until the peak value for calculating the attenuation rate is obtained. When the above expression (2) is used, the CPU21 analyzes the count value and recognizes that a peak corresponding to P6 is obtained.

After calculating the attenuation rate ζ in this manner, the CPU21 determines whether the calculated attenuation rate ζ is equal to or less than a predetermined threshold value (step S2204). That is, the CPU21 determines that the toner in the sub hopper 200 is smaller than the predetermined amount based on the magnitude relationship between the ratio of the count values acquired at different timings and the predetermined threshold value. As illustrated in fig. 18, when sufficient toner remains inside the sub hopper 200, the vibration of the vibration plate 201 is attenuated more rapidly. Therefore, the attenuation rate ζ becomes small.

On the other hand, when the toner in the sub hopper 200 decreases, the damping of the vibration plate 201 is reduced accordingly, and the damping rate ζ increases. Therefore, by setting the attenuation rate ζ corresponding to the toner remaining amount to be detected as a threshold value and based on the calculated attenuation rate ζ, it is possible to determine whether or not the toner remaining amount inside the sub hopper 200 is reduced to the remaining amount to be detected (hereinafter referred to as "predetermined amount").

The remaining amount of toner inside the sub hopper 200 does not directly affect the damping method of the vibration plate 201, but the contact state of the toner with the vibration plate 201 changes according to the remaining amount of toner, and the damping method of the vibration plate 201 is determined. Therefore, even if the amount of the remaining toner in the sub-hopper 200 is the same, if the contact manner of the toner with the vibration plate 201 is different, the attenuation manner of the vibration plate 201 is different.

On the other hand, when the remaining amount of toner in the sub hopper 200 according to the present embodiment is detected, the toner in the sub hopper 200 is constantly stirred by the stirring member 205. Therefore, the contact state of the toner to the vibration plate 201 can be determined to correspond to the toner remaining amount to some extent. This can avoid a problem that the detection result varies depending on the contact manner of the toner with the vibration plate 201 even if the amount of the remaining toner in the sub-hopper 200 is the same.

If the calculated attenuation rate ζ is less than the threshold value as a result of the determination in step S2204 (no in step S2204), the CPU21 determines that a sufficient amount of toner is retained in the sub hopper 200, and ends the process as it is. On the other hand, if the calculated damping rate ζ is equal to or higher than the threshold value (yes in step S2204), the CPU21 determines that the toner amount in the sub hopper 200 is equal to or lower than the predetermined amount, and ends the process after toner empty detection (step S2205).

The CPU21 that detects the toner end by the processing in step S2205 controls the image forming apparatus 100 to output a signal indicating that the remaining toner amount is less than the predetermined amount to the controller on the upper stage. Accordingly, the controller of image forming apparatus 100 recognizes that the toner of the specific color is used up, and can supply the toner from toner tank 117.

Next, the relationship between the frequency of the oscillation signal of the magnetic flux sensor 10 according to the present embodiment, the acquisition cycle (hereinafter referred to as "sampling cycle") of the count value of the CPU21, and the natural frequency of the diaphragm 201 will be described. Fig. 22 is a schematic diagram showing the count value after sampling the vibration of the vibration plate 201 in 1 cycle. In fig. 22, the vibration period of the vibration plate 201 is Tplate, and the sampling period is Tsample.

In the method described with reference to fig. 19 to 21, in order to calculate the damping rate ζ of the diaphragm 201 with high accuracy, it is necessary to obtain the peak value of the vibration of the diaphragm 201 with high accuracy. Therefore, a sufficient number of samples of the count value is required for the Tplate, and thus Tsample is required to be sufficiently small with respect to the Tplate.

In the example of fig. 22, the number of samples of the count value is 10 for one period of Tplate. That is, Tsample is 1/10 for Tplate. According to the embodiment of fig. 22, by sampling reliably during the period of Tpeak in the figure, the peak can be obtained with high accuracy.

Therefore, if the sampling period Tsample of the CPU21 is 1ms, the vibration period Tplate of the vibration plate 201 is preferably 10ms or more. In other words, the natural frequency of the diaphragm 201 is preferably about 100Hz, more preferably less than 100Hz, with respect to 1000Hz of the sampling frequency of the CPU 21. The natural frequency of the diaphragm 201 is realized by adjusting the material of the diaphragm 201, the dimensions such as the thickness of the diaphragm 201, and the weight of the protrusion 202.

On the other hand, if the value of the count value sampled in each sampling period is too small, the count value of each sample corresponding to the vibration of the vibration plate 201 becomes small, and the attenuation rate ζ cannot be calculated with high accuracy. Here, the value of the count value after sampling is based on the oscillation frequency of the magnetic flux sensor 10.

Generally, the oscillation frequency of the magnetic flux sensor 10 is about several MHz, and when sampling is performed at a sampling frequency of 1000Hz, a count value of 1000 or more can be obtained for each sampling timing. Therefore, the attenuation rate ζ can be calculated with high accuracy by the above-described Tplate and Tsample degrees.

However, if the amount of change in the oscillation frequency of the magnetic flux sensor 10 is insufficient for a change in the interval between the magnetic flux sensor 10 and the vibration plate 201 due to the vibration of the vibration plate 201, the amplitude of the vibration for the count value of the time shown in fig. 19 becomes small. As a result, the change in the damping rate ζ becomes small, and the accuracy of toner remaining amount detection by the vibration of the vibration plate 201 also decreases.

In order to increase the amount of change in the oscillation frequency of the magnetic flux sensor 10d with respect to the change in the interval between the magnetic flux sensor 10 and the vibrating plate 201, it is necessary to determine the arrangement interval between the magnetic flux sensor 10 and the vibrating plate 201 based on the characteristics shown in fig. 11. For example, as shown by the arrow section in the figure, it is preferable that the interval included in the range in which the change in the oscillation frequency is steep with respect to the change in the interval between the magnetic flux sensor 10 and the vibration plate 201 is determined as the arrangement interval between the magnetic flux sensor 10 and the vibration plate 201.

Fig. 23 is a schematic diagram showing an adjustment method of the arrangement interval between the magnetic flux sensor 10 and the vibration plate 201. As shown in fig. 23, the adjustment of the arrangement interval g between the magnetic flux sensor 10 and the vibrating plate 201 can be adjusted by the thickness of the frame 200a of the sub-hopper 200 to which the magnetic flux sensor 10 and the vibrating plate 201 are attached, or the thickness of the fixing portion 201a to which the vibrating plate 201 is fixed.

As described above, according to the method of detecting the remaining amount of toner according to the present embodiment, the influence of the toner on a precise phenomenon such as vibration of the vibration plate 201 is detected. Further, unlike a method of directly detecting the pressure of the toner or the like, since the detection is performed by the vibration of the vibrating plate, it is not necessary to use a pressure sensor which is difficult to improve the accuracy, and therefore the remaining amount of the toner in the container can be detected with high accuracy.

In addition, the vibration plate 201, which is an object to be sensed by the magnetic flux sensor 10 employed as the sensor in the present embodiment, is assumed to vibrate. Therefore, if toner adheres to the vibrating plate 201, the adhered toner is shaken off by the vibration, and a decrease in detection accuracy due to the adhesion of toner can be avoided.

In addition, the magnetic flux sensor 10 employed as a sensor in the present embodiment does not need to be in physical contact with the diaphragm 201 as a sensing target. Therefore, even if the magnetic flux sensor 10 is provided outside the container of toner, it is not necessary to form a hole in the frame of the container to ensure physical contact. Therefore, the mounting is easy and the productivity can be improved.

Further, according to the embodiment of the present invention, the detection of the toner remaining amount is performed after the displacement of the vibrating plate 201 pressed by the stirring member 205 is used as a trigger (trigger) and the subsequent peak value is obtained as shown in step S2201. Therefore, the vibration plate 201 cannot obtain a detection result of the toner remaining amount in a state where it is pressed by the stirring member 205 as shown in fig. 14.

In contrast, in the system of detecting the pressure corresponding to the remaining amount of toner by a pressure sensor or the like, it is difficult to distinguish between the pressure pressed by the stirring member stirring the toner in the container and the pressure generated corresponding to the remaining amount of toner, and it is difficult to improve the detection accuracy. According to the embodiment, such a problem can be solved.

In the above embodiment, the diaphragm 201 made of a plate-shaped member made of a metal material is used as an example of the object sensed by the magnetic flux sensor 10. However, this is only one example. The conditions required for the vibration plate 201 are that vibration is generated by a prescribed vibration frequency as illustrated in fig. 22, that the magnetic flux is affected according to a change in the interval from the magnetic flux sensor 10, and that the frequency of the oscillation signal of the magnetic flux sensor 10 is affected.

In the above embodiment, the metal material is used which is close to the magnetic flux sensor 10 to cancel the magnetic flux and reduce the inductance L, but conversely, a ferromagnetic material which is close to the magnetic flux sensor 10 to increase the magnetic flux and increase the inductance L may be used.

In the above embodiment, the diaphragm 201 of the plate-shaped member is set as the sensing target of the magnetic flux sensor 10 in terms of the angle that affects the magnetic flux generated by the planar pattern coil 11 of the magnetic flux sensor 10 or the natural frequency. However, this is only one example, and the present invention is not limited to a plate-like rod-like component as long as the conditions for vibration and influence on the magnetic flux are satisfied.

In the above-described embodiment, the vibration plate 201 is formed of a material having an influence on the amount of magnetic flux, and the damping of the vibration plate 201 is detected by the magnetic flux sensor 10. However, this is only one example, and any method may be used as long as the remaining amount of toner in the container is detected by the influence of the toner on a precise phenomenon such as vibration attenuation of the plate-like member.

Therefore, the same effect as described above can be obtained by providing a function of detecting the vibration of the vibration plate 201 provided in the container, not only by providing the magnetic flux sensor 10 but also by forming the vibration plate 201 of a material that affects the magnetic flux. As such a method, a method of providing a sensor for directly detecting vibration at a position where the vibration of the vibration plate 201 is transmitted is conceivable. The position where the sensor is provided may be the fixing portion 201a, the bump 202, or the like.

The predetermined amount can be adjusted by the arrangement of the vibrating plate 201 and the magnetic flux sensor 10 in the sub-hopper 200. Fig. 24 and 25 are diagrams showing the arrangement of the vibrating plate 201 and the magnetic flux sensor 10 in the sub-hopper 200 and the relationship between the predetermined amounts. In fig. 24, when the height of the toner held inside the sub hopper 200 is lower than the height of the broken line a shown in the figure, the toner does not contact the vibration plate 201. Therefore, in the vicinity of the height of the broken line a in the figure, it can be detected that the toner remaining amount is lower than the prescribed amount.

On the other hand, the arrangement height of the diaphragm 201 and the magnetic flux sensor 10 in fig. 25 is lower than that in fig. 24. Then, when the height of the toner held inside the sub hopper 200 is lower than the height of the broken line B shown in the figure, the toner does not contact the vibration plate 201. Therefore, in the vicinity of the height of the broken line B in the figure, it can be detected that the toner remaining amount is lower than the prescribed amount.

The arrangement of the diaphragm 201 and the magnetic flux sensor 10 as described above can be used to adjust the supply state of toner for each color of CMYK by adjusting a predetermined amount. For example, for colors with high use frequency of CMYK, as shown in fig. 24, the diaphragm 201 and the magnetic flux sensor 10 are disposed relatively high. On the other hand, for a color with a low frequency of use, as shown in fig. 25, the diaphragm 201 and the magnetic flux sensor 10 are arranged relatively low. By this adjustment, the toner can be efficiently supplied according to the frequency of use.

In the above-described embodiment, the mechanism for detecting the remaining amount of toner in the sub hopper 200 shown in fig. 2 is described by taking an example of a configuration including the magnetic flux sensor 10 and the vibration plate 201. However, the above configuration can be widely used as a toner amount for detecting powder, and for example, the configuration may be used as a configuration for detecting a toner remaining amount in the developer 112.

Fig. 26 is a sectional view of the developer 112 in use. Inside the developing unit 112, a supply chamber conveying member 112b and a recovery chamber conveying member 112c, which are screws for conveying toner, rotate and convey toner in the main scanning direction.

When the magnetic flux sensor 10 and the diaphragm 201 are configured in the developing unit 112, the magnetic flux sensor 10 is mounted so that the surface on which the planar pattern coil 11 is formed faces the sensor mounting position 112a in the developing unit 112, as shown in fig. 26. Thus, as shown in fig. 26, the planar pattern coils 11 are arranged so as to face the developer movement spaces connected to the conveyance path of the collection chamber conveyance member 112c and the conveyance path of the supply chamber conveyance member 112 b.

Inside the developer 112, a vibration plate 201 is disposed in the developer movement space. The vibration plate 201 disposed inside the developer 112 vibrates after being sprung open by the revolving recovery chamber conveyance member 112c, as in the case of being provided in the sub hopper 200. Thus, the vibration of the diaphragm 201 can be detected by the magnetic flux sensor 10 in the same manner as described above.

In the developer movement space, since the toner moves between the conveyance path of the collection chamber conveyance member 112c and the conveyance path of the supply chamber conveyance member 112b, the residence time of the toner is longer than that of each conveyance path, and the density of the toner increases. Therefore, as shown in fig. 26, by disposing the vibration plate 201 in the developer movement space, the influence of the toner on the vibration of the vibration plate 201 is increased, and the remaining amount of toner inside the developing device 112 can be detected with high accuracy.

In the above-described embodiment, the toner as the developer used in the electrophotographic image forming apparatus is exemplified as the powder to be detected for the remaining amount. However, this is only an example, and the present invention can be applied similarly to a powder having fluidity and affecting the vibration of the vibrating plate 201 according to the remaining amount, and for example, a pre-mixture in which toner and developer are mixed in advance may be applied. The remaining amount can be detected similarly not only by the powder but also by a liquid as long as the substance has fluidity and affects the vibration of the vibration plate 201 in accordance with the remaining amount.

In the above embodiment, the attenuation ratio ζ is calculated by the above formula (2) as an example. However, this is only one example, and an average value of the attenuation rates between a plurality of peaks may be used as in the following expression (3), for example.

Formula (3)

In addition, as shown in the following formula (4), the ratio of the peaks may be simply adopted.

Formula (4)

In the above-described embodiments, a case in which a planar pattern coil formed by printing wiring on a substrate is used is described as an example. By forming the coil on a plane, the thickness of the diaphragm 201, which is the sensing target, in the direction facing the diaphragm can be reduced, and the device can be appropriately downsized.

However, even if the coil is not formed by a planar pattern, the same effect can be obtained as long as the coil generating the magnetic flux is formed in parallel to the direction facing the vibration plate 201. Fig. 27 and 28 show other examples of the coil formation method. Fig. 27 is a view seen from a direction parallel to the plate surface of the base plate constituting the magnetic flux sensor 10, and fig. 28 is a view seen from a direction perpendicular to the plate surface of the base plate constituting the magnetic flux sensor 10.

In the example of fig. 27 and 30, the coil 11' is formed by winding and arranging a wire whose surface is insulated on a base plate constituting the magnetic flux sensor 10. In the example of fig. 27 and 30, as shown in fig. 27, the thickness in the direction parallel to the direction facing the vibration plate 201 can be made sufficiently thin, and the device can be miniaturized.

Fig. 29 is a perspective view of the vibration plate 201 illustrated in fig. 4. As shown in fig. 29, the above embodiment has been described by way of example in which the projection 202 is provided at an end opposite to an end fixed to the diaphragm 201 by the fixing portion 201 a. Thus, the inclined surface of the stirring member 205 for popping up the vibration plate 201 can be formed by the protrusion 202.

Here, in the example of fig. 29, the projection 202 is provided over the entire width of the vibration plate 201 in the direction in which the stirring member 205 contacts and moves, but as shown in fig. 30, the projection 202 may be provided only in a part thereof. However, in the projection 202, if the inclination angle in the range in which the stirring member 205 is in contact changes halfway as shown in fig. 30, the pressing force changes while the vibration plate 201 is being pressed, as shown in fig. 14, and the vibration after being flicked may be affected. Therefore, the inclination angle of the slope provided on the projection 202 is preferably the same in the contact range of the stirring member 205.

In addition to the mode in which the projection 202 formed by a member different from the vibration plate 201 is disposed at the tip, as shown in fig. 31, a metal piece 201b extending at the end of the vibration plate 201 may be bent to form an inclined portion. As shown in fig. 32, even in the configuration of the diaphragm 201 without the metal piece 201b, the inclined portion may be formed by folding the end portion three-dimensionally.

These methods are effective particularly when a member different from the diaphragm 201 is attached, and an appropriate value as described above cannot be obtained as the natural frequency of the diaphragm 201.

Fig. 33 is a perspective view showing the inside of the sub-hopper 200 according to the modification. In the example of fig. 33, unlike fig. 4, a metal rod 203 is arranged near the diaphragm 201. The metal rod 203 functions to scrape out the toner that has entered between the vibrating plate 201 and the frame body of the sub hopper 200. The function of the metal rod 203 will be explained below. Fig. 34 is a perspective view showing the arrangement of the vibrating plate 201 and the metal rod 203. As shown in fig. 34, the vibrating plate 201 is fixed to the frame of the sub-hopper 200 by a fixing portion 201 a.

As shown in fig. 34, the metal rod 203 includes a rod-shaped portion 203a and a key-shaped portion 203b, and an end portion of the rod-shaped portion 203a is bent at a right angle to form the key-shaped portion 203 b. The rod-shaped portion 203a is disposed in a direction parallel to the longitudinal direction of the diaphragm 201, and the key-shaped portion 203b is disposed to protrude in a direction perpendicular to the plate surface of the diaphragm 201.

Fig. 35 is a side view showing a state before the stirring member 205 comes into contact with the projections 202 attached to the metal rod 203 and the vibrating plate 201 as a state where the rotating shaft 204 rotates. In fig. 35, the rotation shaft 204 and the stirring member 205 are rotated in the clockwise rotation direction.

As shown in fig. 35, the projection 202 has a shape inclined with respect to the plate surface of the diaphragm 201 when viewed from the side. The inclined surface of the projection 202 is a portion pressed by the stirring member 205 when the stirring member 205 is flicked and the vibration plate 201 is vibrated.

As shown in the arrangement of fig. 35, when the stirring member 205 rotates and approaches the vibration plate 201, it first comes into contact with the key-shaped portion 203b and pushes down the metal rod 203 before coming into contact with the protrusion 202. Fig. 36 is a side view showing a state in which the stirring member 205 further rotates from the state shown in fig. 35. As shown in fig. 36, by the key-shaped portion 203b being pushed down by the rotation of the stirring member 205, the entire metal rod 203 is bent and pushed down.

Further, the stirring member 205 rotates in a state of contacting the projection 202, and the vibration plate 201 is pressed with the inclination of the projection 202. In fig. 36, the positions of the diaphragm 201 and the bump 202 in a stable state when no external force is applied are shown by broken lines. As shown in fig. 36, the vibrating plate 201 and the projection 202 are pressed by the stirring member 205.

Fig. 37 is an upper view showing the state shown in fig. 36. Since the vibration plate 201 is fixed to the frame of the sub-hopper 200 by the fixing portion 201a, the position of the fixing portion 201a side does not change. On the other hand, the end opposite to the free end where the projection 202 is provided is pushed by the stirring member 205 and then moves on the side opposite to the side where the rotation shaft 204 is provided. As a result, the diaphragm 201 is bent with the fixing portion 201a as a base point as shown in fig. 37. In the state of being thus bent, energy for vibrating the vibration plate 201 is accumulated.

Fig. 38 is a perspective view showing the state of the metal rod 203 in the state shown in fig. 36. As shown in fig. 38, the metal rod 203 is pushed downward by the stirring member 205, and enters between the vibrating plate 201 and the inner wall of the frame of the sub hopper 200, and is bent. Thereby, the metal rod 203 scrapes off the toner between the vibrating plate 201 and the inner wall of the frame body of the sub hopper 200.

As described above, the vibration plate 201 obtains energy for vibration because it is pushed and bent by the stirring member 205. Therefore, when the toner is trapped between the vibrating plate 201 and the inner wall of the frame body of the sub hopper 200, the vibrating plate 201 is not sufficiently pressed, and energy for the vibration of the vibrating plate 201 is not sufficiently accumulated.

On the other hand, as shown in fig. 38, since the metal rod 203 enters between the vibrating plate 201 and the inner wall of the frame body of the sub hopper 200 to scrape out the toner, a bending space of the vibrating plate 201 for accumulating energy only for vibration is secured.

The broken line in fig. 39 shows the range of movement of the metal rod 203 after being pushed downward. In the present embodiment, the metal rod 203 does not enter the entire area of the plate surface of the diaphragm 201, and as shown in fig. 39, the metal rod 203 enters a predetermined area above the plate surface. Accordingly, the toner clogged between the vibration plate 201 and the inner wall of the housing of the sub hopper 200 can be scraped off by the space secured and bent by accumulating only the energy for vibrating the vibration plate 201.

The present invention has specific effects in the following various modes.

(mode A)

A powder detection device for detecting the remaining amount of a powder having fluidity in a container, comprising: a vibrating section that is disposed inside the container and vibrates under the influence of the powder inside the container; a vibration detection unit that detects a vibration state of the vibration unit; a vibration imparting portion that causes the vibrating portion to vibrate; and a detection processing unit that detects the remaining amount of the powder in the container based on a detection result of the vibration detection unit.

(mode B)

The powder detection device according to mode a, characterized in that: the vibration applying section is a stirring section for stirring the powder in the container.

(mode C)

The powder detection device according to mode a or mode B, characterized in that: the vibration applying part is attached to a rotation shaft that rotates in the container, rotates together with the rotation shaft, and vibrates the vibration part after bending the vibration part during rotation, and one end of the vibration part in a direction parallel to the axial direction of the rotation shaft is formed by a fixed plate-shaped member, and the other end is provided with a protruding part that is pressed by the vibration applying part.

(mode D)

The powder detection device according to mode C, characterized in that: the protruding portion has a protruding inclined surface with respect to the plate surface of the vibration portion, and the inclined surface is formed so as to be close to the rotation axis along the rotation direction of the vibration applying portion.

(mode E)

The powder detection device according to mode D, characterized in that: the inclined surfaces are inclined at the same angle in a range in which the vibration imparting portions are in contact.

(mode F)

The powder detection device according to mode C or mode D, characterized in that: the protruding portion is made of a material different from that of the vibrating portion, and the vibration frequency of the entire vibrating portion including the protruding portion is equal to or lower than a predetermined value.

(mode G)

The powder detection device according to any one of modes a to F, characterized in that: the vibration detection unit is an oscillation unit that outputs a frequency signal corresponding to a state of magnetic flux that passes through an opposing space, the oscillation unit is configured to vibrate in a direction opposing the oscillation unit while opposing the housing of the container and the oscillation unit with the housing of the container therebetween, and is formed of a material that affects the magnetic flux, and the detection processing unit acquires frequency-related information regarding the frequency of the oscillation signal of the oscillation unit at a predetermined cycle, detects a vibration state of the oscillation unit from a change in the frequency-related information that changes in accordance with the vibration of the oscillation unit, and detects a remaining amount of powder in the container from a result of the detection.

(mode H)

The powder detection device according to mode G, characterized in that: the detection processing unit detects the vibration state of the vibration unit based on a change in the frequency-related information that changes in accordance with the attenuation of the vibration unit caused by the function of the vibration applying unit.

(mode I)

The powder detection device according to mode H, characterized in that: the detection processing unit acquires, as the frequency-related information, a count value of an oscillation signal of the oscillation unit in each of the predetermined periods, and detects a vibration state of the oscillation unit based on a change in the count value.

(mode J)

The powder detection device according to mode I, characterized in that: the detection processing unit acquires, as the frequency-related information, a count value of an oscillation signal of the oscillation unit in each of the predetermined periods, and detects a vibration state of the oscillation unit based on a ratio of the count values acquired at different timings.

(mode K)

The powder detection device according to mode J, characterized in that: the detection processing unit detects that the remaining amount of the powder in the container is less than a predetermined amount based on a magnitude relationship between the ratio of the count value and a predetermined threshold value.

(mode L)

The powder detection device according to any one of modes G to K, characterized in that: the detection processing unit obtains the frequency-related information at a cycle not more than a predetermined ratio with respect to a vibration cycle of the vibration unit.

(mode M)

The powder detection device according to any one of modes G to L, characterized in that: the oscillating part includes a coil formed on a base plate to generate a magnetic flux in a direction opposite to the vibrating part and output a frequency signal corresponding to an inductance of the coil.

(mode N)

An image forming apparatus provided with a remaining amount detection device that detects a remaining amount of powder for image formation, characterized in that: the remaining amount detection device is the powder detection device according to any one of modes a to M.

(mode O)

A powder detection method for detecting a remaining amount in a container of a powder having fluidity, the method comprising: vibrating a vibrating section which is disposed inside the container and vibrates under the influence of the powder inside the container; detecting a vibration state of the vibration part by a vibration detection part; the remaining amount of the powder in the container is detected based on a detection result of the vibration detection unit.

(mode P)

The powder detection method according to mode O, characterized in that: the vibration detection unit is an oscillation unit that outputs a frequency signal corresponding to a state of magnetic flux passing through the opposing space, the vibrating portion is configured to vibrate in a direction opposite to the oscillating portion while facing the oscillating portion with the frame of the container interposed therebetween, and is formed of a material that affects magnetic flux, the powder detection method causing the vibrating portion to vibrate, and outputs a frequency signal corresponding to the state of the magnetic flux passing through the opposing space through the oscillating portion, and frequency-related information on the frequency of the oscillation signal of the oscillation unit is acquired at a predetermined cycle, and detects a vibration state of the vibration part according to a change in the frequency-related information that changes in correspondence with the vibration of the vibration part, and detecting the remaining amount of the powder in the container based on a detection result of the vibration state of the vibration unit.

(mode Q)

The powder detection device according to any one of modes a to P, characterized in that: the vibration unit is disposed opposite to a frame constituting the container, and a powder removing unit is provided to remove powder between the vibration unit and the frame by deformation of the vibration applying unit.

(mode R)

The powder detection device according to any one of modes a to Q, characterized in that: the vibration unit is a metal plate having a plate surface perpendicular to the direction facing the oscillation unit.

Claims

1. A powder detection device for detecting the remaining amount of a powder having fluidity in a container, comprising:

a vibrating section that is disposed inside the container and vibrates under the influence of the powder inside the container;

a vibration detection unit that detects a vibration state of the vibration unit;

a vibration imparting portion that causes the vibrating portion to vibrate;

a detection processing unit for detecting the remaining amount of the powder in the container based on the detection result of the vibration detection unit and detecting the remaining amount of the powder in the container

Wherein the vibration applying part is attached to a rotation shaft that rotates in the container, rotates together with the rotation shaft, and vibrates the vibration part after bending the vibration part during rotation, and one end of the vibration part in a direction parallel to the axial direction of the rotation shaft is formed by a fixed plate-shaped member, and the other end is provided with a protrusion that is pressed by the vibration applying part.

2. The powder detection apparatus according to claim 1, wherein:

the vibration applying section is a stirring section for stirring the powder in the container.

3. The powder detection apparatus according to claim 1, wherein:

the protruding portion has a protruding inclined surface with respect to the plate surface of the vibration portion, and the inclined surface is formed so as to be close to the rotation axis along the rotation direction of the vibration applying portion.

4. The powder detection apparatus according to claim 1, wherein:

the protruding portion is made of a material different from that of the vibrating portion, and the vibration frequency of the entire vibrating portion including the protruding portion is equal to or lower than a predetermined value.

5. The powder detection apparatus according to any one of claims 1 to 4, characterized in that:

the vibration detection unit is an oscillation unit that outputs a frequency signal corresponding to a state of magnetic flux that passes through an opposing space, the oscillation unit is configured to vibrate in a direction opposing the oscillation unit while opposing the housing of the container and the oscillation unit with the housing of the container therebetween, and is formed of a material that affects the magnetic flux, and the detection processing unit acquires frequency-related information regarding the frequency of the oscillation signal of the oscillation unit at a predetermined cycle, detects a vibration state of the oscillation unit from a change in the frequency-related information that changes in accordance with the vibration of the oscillation unit, and detects a remaining amount of powder in the container from a result of the detection.

6. The powder detection apparatus according to claim 5, wherein:

the detection processing unit detects the vibration state of the vibration unit based on a change in the frequency-related information that changes in accordance with the attenuation of the vibration unit caused by the function of the vibration applying unit.

7. The powder detection apparatus according to claim 6, wherein:

the detection processing unit acquires, as the frequency-related information, a count value of an oscillation signal of the oscillation unit in each predetermined period, and detects a vibration state of the oscillation unit based on a change in the count value.

8. The powder detection apparatus according to claim 7, wherein:

the detection processing unit acquires, as the frequency-related information, a count value of an oscillation signal of the oscillation unit in each predetermined period, and detects a vibration state of the oscillation unit based on a ratio of the count values acquired at different timings.

9. The powder detection apparatus according to claim 8, wherein:

the detection processing unit detects that the remaining amount of the powder in the container is less than a predetermined amount based on a magnitude relationship between the ratio of the count value and a predetermined threshold value.

10. The powder detection apparatus according to claim 5, wherein:

the detection processing unit obtains the frequency-related information at a cycle not more than a predetermined ratio with respect to a vibration cycle of the vibration unit.

11. The powder detection apparatus according to claim 5, wherein:

the oscillating part includes a coil formed on a base plate to generate a magnetic flux in a direction opposite to the vibrating part and output a frequency signal corresponding to an inductance of the coil.

12. An image forming apparatus provided with a remaining amount detection device that detects a remaining amount of powder for image formation, characterized in that:

the remaining amount detection device is the powder detection device according to any one of claims 1 to 11.

13. A powder detection method for detecting the remaining amount of a powder having fluidity in a container, comprising:

a vibration imparting unit configured to vibrate a vibrating unit, which is disposed inside the container and vibrates under the influence of the powder inside the container, by a vibration;

detecting a vibration state of the vibration part by a vibration detection part;

detecting the remaining amount of the powder in the container based on the detection result of the vibration detecting unit, and detecting

14. The powder detection method according to claim 13, wherein:

the vibration detection unit is an oscillation unit that outputs a frequency signal corresponding to a state of magnetic flux passing through the opposing space, the vibrating portion is configured to vibrate in a direction opposite to the oscillating portion while facing the oscillating portion with the frame of the container interposed therebetween, and is formed of a material that affects magnetic flux, the powder detection method causing the vibrating portion to vibrate, and outputs a frequency signal corresponding to the state of the magnetic flux passing through the opposing space through the oscillating portion, and frequency-related information on the frequency of the oscillation signal of the oscillation unit is acquired at a predetermined cycle, and detects a vibration state of the vibration part according to a change in the frequency-related information that changes in correspondence with the vibration of the vibration part, and detecting the remaining amount of the powder in the container based on a detection result of the vibration state of the vibration unit.